Source: Authors' analysis of Current Population Survey Outgoing Rotation Group microdata

Updated May 17, 2012

Documentation and methodology

“Percent union” is tabulated from CPS-ORG data (see Appendix B) and includes all those covered by unions. “Union premium” values are the coefficients on union in a model of log hourly wages with controls for education, experience as a quartic, marital status, region, industry (12) and occupation (9), race/ethnicity, and gender where appropriate. For this analysis we only use observations that do not have imputed wages because the imputation process does not take union status into account and therefore biases the union premium toward zero. See Mishel and Walters (2003). As with other CPS microdata analyses presented in the book, race/ethnicity categories are mutually exclusive (i.e., white non-Hispanic, black non-Hispanic, and Hispanic any race).